C-O isotopic composition and genesis of the Jinbiansi uranium deposit in Gansu Province

Abstract: C-O isotope analysis of calcite closely related to the mineralization of the Jinbian Temple uranium deposit in the eastern section of the Longshoushan metallogenic belt has been conducted, and the results show that these calcite samples have δ The 13CVPDB value is - 3.8 ‰ to+1.4 ‰, with an average of - 1.4 ‰; δ The 18OVSMOW value ranges from 17.5 ‰ to 25.8 ‰, with an average of 23.1 ‰, which is basically consistent with the C-O isotope composition of marine carbonate. Therefore, it is speculated that the carbon in this area may mainly come from the marine carbonate formation in the Precambrian basement. Based on the analysis of regional geological characteristics, it is believed that the Phnom Penh Si uranium deposit is of mixed genesis of eluviation and hydrothermal solution. The early regional alkaline metasomatic hydrothermal mineralization formed a ore-bearing alteration zone, and the shallow eluviation type uranium ore body was formed by the superposition of groundwater oxidation and transformation in the later stage.